Classification of Knee Osteoarthritis

STAGES OF FEMEROTIBIAL OSTEOARTHRITIS

 

REPICCI
Stage I Articular surface involvement only.
Stage II Sclerotic bone response to complete loss of articular cartilage.
Stage III Failure of sclerotic bone, failure of the joint as a functioning unit.

Ahlback utilizes a 5 stage system, dividing Repicci stage II into 3 additional stages. Ahlback stage 2,3,4 effectively demonstrate the slow, predictable progression of unicompartmental knee sclerotic stage osteoarthritis.

Bauer, Knutson, Lindstrand, Ryd, and Stenstrom of Lund University Sweden, reported on 370 osteoarthritic knees classified radiographically.

Medial compartment involvement occurred at a frequency six times greater than lateral involvement.
Only 2% of patients presented with both medial and lateral involvement at the same time. Over 50% of patients presented with patellofemoral involvement.

Although 50% of osteoarthritic patients present with patellofemoral involvement radiographically, and a larger percentage noted visually when unicompartmental arthroplasty is performed, Knutson, and Lidgren noted on review of 535 unicompartmental knee arthroplasty revisions only 5% were revised due to patellofemoral symptomatology.